There are many different types of welders used to fuse pieces of metal together. The different types of welders are generally put into two categories which depend on the energy source employed. One category of welders uses an energy source within the work pieces to be welded together. These types of welders include electric resistance welding, friction welding, diffusion welding, explosive welding, and ultrasonic welding. The other category of welders uses an external energy source, such as a flame, an electric arc, an electron beam, a laser beam, or a plasma jet. This second category is the most widely used in industry, except the automotive industry, where resistance welding is typically used. Electric arc welding, however, is by far the most widely-used technique for the welding of metals and alloys.
There are generally two different types of arc welding processes. One type uses a coated welding tip and the other type uses a consumable welding tip. The coated electrode is used less than the consumable electrode because of its lower productivity. However, the coated electrode generally provides higher quality welds. Arc welders can use different types of gasses which are ignited by the electric arc. For example, one type of arc welder uses oxy-acetylene welding because the gas includes a mixture of oxygen and acetylene gas. Another type of arc welder uses a metal inert gas (MIG) which is typically a mixture of carbon and argon gas. The carbon and argon gas form an envelope around the welding joint to push oxygen out of the way so that a better weld can be provided.
In any case, the energy source and/or the ignited gas both generate a tremendous amount of light which can damage the eyes of an operator using the welder. To reduce this damage, the operator typically wears a helmet with a window to look through. The window is made of a material which blocks out the eye damaging light. Unfortunately, the window also blocks out visible light so that the operator has difficulty seeing outside the helmet without raising it up. This causes several problems. For example, it is inconvenient and more difficult to work efficiently. Further, the operator is essentially blind when the helmet is down and the welder is off. This can be dangerous when working in a hazardous work environment. Accordingly, there is a need for a welder which allows the operator to see better when the helmet is down.